While the Music V software synthesis approach was somewhat general and
powerful--a unit generator could do anything permitted by the underlying
programming language--computational costs on a general-purpose computer
were dauntingly high. It was common for composers to spend hundreds of
seconds of computer time for each second of sound produced. Student
composers were forced to work between 3 AM and 6 AM to finish their pieces.
Pressure mounted to move the primitive sound-generating algorithms into
special-purpose hardware.

In October 1977, CCRMA took delivery of the Systems Concepts Digital
Synthesizer [5], affectionately known as the ``Samson Box,'' named
after its designer Peter Samson. The Samson Box resembled a green
refrigerator in the machine room at the Stanford Artificial Intelligence
Laboratory, and it cost on the order of $100,000. In its hardware
architecture, it provided 256 generators (waveform oscillators with several
modes and controls, complete with amplitude and frequency envelope
support), and 128 modifiers (each of which could be a second-order filter,
random-number generator, or amplitude-modulator, among other functions).
Up to 64 Kwords of delay memory with 32 access ports could be used to
construct large wavetables and delay lines. A modifier could be combined
with a delay port to construct a high-order comb filter or Schroeder
allpass filter--fundamental building blocks of digital reverberators.
Finally, four digital-to-analog converters came with the Box to supply
four-channel sound output. These analog lines were fed to a 16-by-32 audio
switch that routed sound to various listening stations around the lab.

The Samson Box was an elegant implementation of nearly all known,
desirable, unit-generators in hardware form, and sound synthesis was sped
up by three orders of magnitude in many cases. Additive, subtractive, and
nonlinear FM synthesis and waveshaping were well supported. Much music was
produced by many composers on the Samson Box over more than a decade. It
was a clear success.

The Samson Box, however, was not a panacea. There were sizable costs in
moving from a general software synthesis environment to a constrained,
special-purpose hardware synthesizer. Tens of man-years of effort went
into software support. A large instrument library was written to manage the
patching of hardware unit generators into instruments. Instead of directly
controlling the synthesizer, instrument procedures written in the SAIL
programming language were executed to produce synthesizer commands that
were saved in a ``command stream'' file. Debugging tools were developed
for disassembling, editing, and reassembling the synthesizer command-stream
data. Reading and manipulating the synthesizer command stream was
difficult but unavoidable in serious debugging work. Software for managing
the unique envelope hardware on the synthesizer was developed, requiring a
lot of work. Filter support was complicated by the use of 20-bit
fixed-point hardware with nonsaturating overflow and lack of rounding
control. General wavetables were not supported in the oscillators.
Overall, it simply took a lot of systems programming work to make
everything work right.

Another type of cost was incurred in moving from the general-purpose
computer to the Samson Box. Research into new synthesis techniques slowed
to a trickle. While editing an Algol-like description of a Mus10
instrument was easy, reconfiguring a complicated patch of Samson Box
modules was much more difficult, and a lot of expertise was required to
design, develop, and debug new instruments on the Box. Many new techniques
such as waveguide synthesis and the Chant vocal synthesis method did not
map easily onto the Samson Box architecture. Bowed strings based on a
physical model could not be given a physically correct vibrato mechanism
due to the way delay memory usage was constrained. Simple feedback FM did
not work because phase rather than frequency feedback is required. Most
memorably, the simple interpolating delay line, called Zdelay in Mus10, was
incredibly difficult to implement on the Box, and an enormous amount of
time was expended trying to do it. While the Samson Box was a paragon of
design elegance and hardware excellence, it did not provide the proper
foundation for future growth of synthesis technology. It was more of a
music instrument than a research tool.